A conventional slicer converts an analog input signal into a rail-to-rail (e.g., digital) output signal. For example, the slicer may incorporate a threshold detection mechanism to generate a digital high or low output signal when the value of the input signal corresponds to a high or low threshold value, respectively. A typical differential slicer generates a high or low output signal based on the zero crossing of the differential input signal.
In many applications the input signal may include a DC component (e.g., a common mode voltage level of a differential input signal). In this case, provisions may be made to insure that the correct threshold value is used to slice the input signal.
A typical conventional slicer incorporates a self-biasing resistor and an AC coupling capacitor. Here, the capacitor removes the DC component of the input signal. In addition, the self-biasing property of the inverter adjusts the DC level of the input signal to a level that causes the output of the inverter to switch when the input signal is at the appropriate level.
In many applications relatively large capacitors and resistors are needed for such a slicer. As a result, this type of slicer may be impractical for some applications.
In addition, these types of slicers may have high pass filtering properties. That is, they may not efficiently process low frequency signals. Accordingly, a need exists for improved slicing circuits.